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https://issues.apache.org/jira/browse/YARN-7935?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16416582#comment-16416582
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Eric Yang commented on YARN-7935:
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[~suma.shivaprasad] Docker embedded DNS will use /etc/resolv.conf from host,
and filter out local IP addresses (127.0.0.1 etc), if no entires are available,
it will route to 8.8.8.8. If RegistryDNS is listed in host machine
/etc/resolv.conf, then it will be used. There is no need to manually redefine
network alias or CONTAINER_HOSTNAME for spark workload to run. I don't think
we can modify Hadoop code to support docker's user-defined network in 2018
because docker heavily use of NAT to accomplish user defined network. This
doesn't work today with Hadoop because Hadoop only understand 1 dimensional
network due to constrain check of client and server/IP mapping for preventing
replay attack. Hence, the proposed feature of use --link=CONTAINER_NAME:ALIAS
for docker embedded DNS might not work as well as you have hoped for Hadoop
3.x.
> Expose container's hostname to applications running within the docker
> container
> -------------------------------------------------------------------------------
>
> Key: YARN-7935
> URL: https://issues.apache.org/jira/browse/YARN-7935
> Project: Hadoop YARN
> Issue Type: Sub-task
> Components: yarn
> Reporter: Suma Shivaprasad
> Assignee: Suma Shivaprasad
> Priority: Major
> Attachments: YARN-7935.1.patch, YARN-7935.2.patch, YARN-7935.3.patch
>
>
> Some applications have a need to bind to the container's hostname (like
> Spark) which is different from the NodeManager's hostname(NM_HOST which is
> available as an env during container launch) when launched through Docker
> runtime. The container's hostname can be exposed to applications via an env
> CONTAINER_HOSTNAME. Another potential candidate is the container's IP but
> this can be addressed in a separate jira.
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